摘要
为从重金属污染土壤中筛选耐镉菌株,并研究其对重金属镉的耐受能力、吸附效果,以及在重金属镉胁迫下的最佳吸附条件,以期为微生物法去除重金属提供优良真菌,采用梯度浓度驯化以及平板划线得到一株高耐镉菌株,进行形态观察和ITSrDNA序列分析。通过单因素实验探究菌株最适生长条件;通过计算耐受性系数对菌株的重金属耐受性进行评估;使用AAS法检测菌株对不同浓度Cd2+的吸附率。经研究发现:菌株最适生长条件为:pH=6,温度25℃,最适接种量7.5%;该菌株在含Cd2+为9000mg/L的平板上仍能生长;在含镉40mg/L的液体培养基中,吸附率达98%,在Cd2+浓度达1000mg/L时,吸附率为92%。说明该菌株具有对镉的高耐受性、高吸附率,为微生物法去除重金属的微生物应用提供新的选择,也为研究高耐受重金属丝状真菌的耐受机制提供了材料。
Cadmium tolerant strains were screened from heavy metal contaminated soil,and their tolerance,adsorption effect on heavy metal cadmium were studied,as well as the best adsorption conditions under the stress of heavy metal cadmium.A fungus was isolated and purified from the soil near the chemical plant and ITS r DNA sequence was analyzed.The optimal growth condition of strain was investigated by single factor experiment.The tolerance coefficient was calculated to evaluate the heavy metal tolerance of the strain.AAS method was used to detect the adsorption rate of Cd2+at different concentrations.The optimal growth conditions of the strain were:pH=6,temperature25℃,optimal inoculation amount 7.5%.The strain can still grow on a plate containing 9000 mg/L Cd2+.In the liquid medium containing 20 mg/L of cadmium,the adsorption rate can be as high as97.4%,and at the Cd2+concentration as high as 1000 mg/L,the adsorption rate is 92%.Conclusion:the strain has a high tolerance to cadmium and a high adsorption rate,which provides a new choice for the microbial application of heavy metal removal by microbial method,and also provides materials for the study of the mechanism of heavy metal resistance of highly resistant filamentous fungi.
作者
余甜甜
张丽杰
马争发
张湄
谭维群
吴前林
YU Tiantian;ZHANG Lijie;MA Zhengfa;ZHANG Mei;TAN Weiqun;WU Qianlin(Department of Pharmacy and Biological Engineering,Chongqing University of Technology,Chongqing 404100,China)
出处
《重庆理工大学学报（自然科学）》
CAS
北大核心
2021年第1期214-221,共8页
Journal of Chongqing University of Technology：Natural Science
基金
重庆市技术创新与应用示范专项社会民生类重点研发项目(cstc2018jscx-mszdX0005)。
关键词
丝状真菌
高镉耐受性
白僵菌
filamentous fungi
high cadmium tolerance
Beauveria bassiana
